Boiler



' UNITED. STATES PATENT OEFIC. i.

HENRY WARDEN, or 'rniLADnLPHIm PENNSYLVANIA.

BOILER.'

SPECIFICATION forming' part of Letters Patent No. 377,792, dated February 14, 1888.

Application med July 9, 1887. serial No. 243,326. (No model.)

To all whom it may concern.-

Be it known that I, HENRY WARDEN, of the city and county of PhiladelphiapState of Pennsylvania, have invented a new and useful Improvement in Boilers, of which the following is a true and exact description, reference being had to the accompanying drawings,which form a part of this specication.

My invention relates to the construction of tubular boilers, and is applicable to all such boilers of this class as have tube-sheets. It is well known that in'the ordinary cylindrical tubular boiler with flat tube-sheets at its ends the pressure of the steam exerts a great and harmful strain upon the ends of the boiler,and that these heads require bracing to enable them to properly resist such pressure. It is my object to strengthen the ends of such boilers and obviate the necessity of braces, while at the same time I provide for the easy'and secure fastening of the firetubes in the tube-sheets. rlhis I accomplish by making the boiler-heads of a dished form, and so indenting their curved faces as to form straight or nearly straight surfaces at or nearly at right angles to the tubes, in which surfaces the tube holes -are formed.

Reference is now had to, the drawings, which show boilers constructed in accordance A with my invention, and in which Figurel is the shell-of the boiler.

a side View of my improved boiler; Fig. 2, an end view of my boiler or its head constructed in the way preferred by me. Fig. 3 is a central sectional elevation of the end of a boiler embodying'my invention in the preferred form shown in Fig. 2. Fig. 4 is an end viewvof a boiler-head, such as are shown in Fig. 1; and

lFig. 5 is a perspective view of one end of a boiler, in which the tube-holes are formed in indentations madein both of the ways shown in the other figures.

A is the boiler; B, thc boiler-heads or tubesheets made in a dished form, as shown, and provided with the flange b, for securing it to In the dished heads B, I form depressionsor indentations D,with their bottoms made dat, or nearly so, and in planes running substantially at right angles to the axes of the boiler. These depressions I prefer to make independent of each other and one for each boiler-tube, as is shown in Figs. 2' and 3 and in the inner tube-row of Fig. 5, as by this device the spherical surface of the dished head B is less broken, and consequently C G, tc., are the fire-tubes, which enter the tubeholes formed in the Hat bottoms of the indentations D, and are secured therein by expanding, or in any ordinary way. lI prefer` in all cases to make the indentations D in concentric rings, as shown, all indentati ons at the same distance from the center having their flat bottoms formed in the same transverse plane, as by thisconstruction the required length of the tubes is easily ascertained and one standard length of tube will serve for each concentric row of tubes.

The advantages of myy new method of constructing boilers will be apparent to all skilled in the art. the boiler-heads enables them to resist the pressure of the steam without braces or undue strain on the tubes, and the flat-bottomed in-- dentations formed in the dished heads enable me to make the tube-holes in a plain surface at right angles, or'nearly at right angles, to the axes of the tubes,which, as is well known, is an important matter as affecting the strength and perfection of the joint made by the tube and tubesheet.

The curved or dished form of The dished and indented heads B maybe 'Y fiat-bottomed indentations D formed thereinA i and perforated for the reception ofthe boilertubes.

2. As a new article of manufacture, a boilerhead, B, of dished form, and having fiat-bottomed indentations D formed therein in con- Acentric ringsfor the reception of the boilertubes.

3. As a new article of manufacture, a tubu .lar boiler-head, B, of dished form, and having IOO separate and independent fiat-bottomed indentations D formed therein and perforated for the reception of the boiler-tubes.

4. As a new article of manufacture, a boilerhead of dished form and having separate and independent fiat bottomed indentations D 'formed therein in concentric rings for the reception of the boi1er-tnbes.

5. A tubular boiler, A, having tubes C running through it from end to end, and one or more heads or tube-sheets, B, of dished form, provided with flat-bottomed indentations D formed therein for the reception of the said tubes C.

6. A tubular boiler, A, having one or more heads or tubesheets, B, of dished form, provided With fiat bottomed indentations D formed therein in concentric rings for the reception of the tubes C.

7. A tubular boiler, A, having tubes C running through it from end to end, and one or 9. In a tubular boiler, the combination of 3o two heads or tube-sheets, B B, each of dished form and provided with dat-bottomed indentations D, with tubes -C running through the boiler and having their ends secured in the said indentations D.

HENRY VVARDEN. Witnesses:

LIsLE S'roKEs, JOSHUA MATLAGK, Jr. 

